No, that's just a conjugate designed to flatten the impedance curve. It counters the impedance rise of the LF voice coil. I've posted those types of curves before on the forum but where they would be I haven't a clue.
Sometimes JBL would use a single parallel resistor and sometimes they'd use a full conjugate (zobel). Sometimes they'd use nothing. The LX30 was a wee bit more expensive than the N65 so the conjugate got "paid for".
A good example would be the 3113B versus the N96/N112/N150A. The conjugate was left out of the low pass of the N96/N112/N150A and the capacitor on the LE5 was changed accordingly. It's no small wonder why we tended to use the "more expensive" 3113B network in our personal L96's, L112's, and L150A's.